People tend to think that “health experts” don’t get how real people live. But you know what? I do.

That’s because I’m a mom, I have a career, and I have a to-do list that’s a mile long. So one thing I know first-hand is that it’s tough to fit in a workout when life is hectic.

But here’s the thing: the benefits of exercise are so powerful that working out isn’t an option—it’s a must. And here’s good news: your exercise routine doesn’t need to take as long as you think.

Today, I’m sharing my top five reasons to work out and my three favorite forms of exercise—plus my easiest “cheat” when you don’t have time for a 20-minute workout.

Why is exercise so important?

You already know that exercise is good for you, but you might not know ALL of the benefits you get from it. Here are five big reasons why movement is medicine:

1. Exercise helps you turn back the clock on the cellular level.

If you heard about a powerful anti-aging drug on TV, would you beg your doctor for it? Well, you don’t need to… because it’s exercise, and it’s free!

In one study, for instance, researchers analyzed the telomeres of nearly 6,000 people. Telomeres are the caps on the ends of your chromosomes—kind of like the tips on the ends of your shoelaces—and as you age, they get shorter and shorter, leading to DNA damage.

Remarkably, the researchers found that people who exercised the most had much longer telomeres than sedentary people. In fact, the difference amounted to about nine years of cellular aging! That’s a big payoff for simply working out.

2. Exercise lowers your risk of disease.

Exercise is one of your most powerful defenses against disease. For instance, women have a 12% to 21% lower risk of breast cancer when they exercise, and physical activity lowers the risk of colon cancer by 19%. Exercise also lowers your risk of everything from obesity to diabetes to Alzheimer’s disease to stroke.

3. Exercise makes you beautiful.

Exercise pumps blood to your skin, bringing it the nutrients it needs to cleanse, nourish, and rejuvenate itself. Think of it as “spring cleaning” for your cells and the fluid surrounding them. And exercises that rush blood to your face, like a yoga downward-facing dog, can make you look more radiant for hours afterward.

4. Exercise helps you sleep better.

Do you lie awake tossing and turning? Then try an early-morning or early-evening workout, and I think you’ll be surprised at how much your sleep improves—especially if you’re near or at menopause, when getting a good night’s sleep can be particularly tricky. One recent study, for instance, found that both aerobic and resistance exercises helped post-menopausal women with insomnia find relief.

5. Exercise makes you happier.

Think of exercise as a “happiness pill.” In one recent large-scale study, researchers found that all types of exercise—from team sports to cycling to gym workouts—can reduce mental health problems. In particular, exercise can help to reduce anger, depression, or anxiety, which is why growing numbers of psychologists and psychiatrists now “prescribe” workouts.

So here are the three ways I like to exercise… plus my favorite seven-minute “cheat”.

I’m a big fan of all forms of exercise, but there are three types I love the best: slow-movement exercises (like dance, yoga and Tai Chi), resistance training, and high-intensity interval training (HIIT). Here’s why I hope you’ll do all three… and why HIIT in particular is your solution when time is tight.

1. Try slow movement exercises.

Exercises like yoga and Tai Chi are potent stress relievers and mood enhancers—and they’re also powerful pain relievers. For instance, one study found that just 12 weeks of Tai Chi helped sufferers from chronic fibromyalgia to reduce their symptoms. A researcher involved in the study commented, “We definitely saw better results than reported in trials of drug treatments for fibromyalgia.’” Other studies show that yoga can help to relieve neck pain, back pain, and pain caused by arthritis.

2. Work-in resistance training.

In resistance training, you use weights, stretch bands, or the weight of your own body to work your muscles against resistance. Resistance training actually creates microscopic tears in your muscles, and when your body repairs these tears, your muscles become stronger.

Research shows that resistance training is one of the best strategies you can use to fight aging. In one study, for instance, researchers took muscle biopsies from young and old participants, had them do resistance training for twenty-six weeks, and then took new muscle biopsies. Amazingly, a whole host of genes associated with aging had reversed their expression in both young and old participants—meaning that these people didn’t just slow but actually started to reverse the aging process!

3. Don’t forget HIIT

In HIIT workouts, you alternate between intervals of high-intensity and low-intensity exercise. For instance, you may sprint as hard as you can on your bike for twenty seconds and then pedal slowly for one minute, repeating these intervals multiple times.

HIIT dramatically raises your levels of human growth hormone, an anti-aging hormone In addition, it causes your cells to make more proteins for your mitochondria (the “power plants” of your cells), slowing the aging process. Researchers report that younger participants doing HIIT have a 49% increase in mitochondrial capacity compared to non-exercising peers, while older participants have an astonishing 69% increase.

What’s more, HIIT burns fat—especially that stubborn belly fat—like crazy. Scientists looking at the effects of HIIT involving bicycle sprints found that it causes the body to release extra amounts of hormones called catecholamines, which drive the release of abdominal fat.

And here’s that amazing “cheat” I told you about—you can get results from just seven minutes of HIIT per day! Here’s how to do it.

Yes, it’s intense, just like the name says. But seriously—only seven minutes! Better yet, this workout combines HIIT and resistance training, so you get the benefits of both in one package. And it’s flexible, so feel free to switch out activities you don’t like (for instance, I’m not a fan of crunches) for other high-intensity activities. Also, be sure to start gradually and increase your intensity with practice.

Make me a promise…

All three of my favorite forms of exercise are dynamite when it comes to helping you look better, feel better, and live longer. And no matter how busy your life is, I’m betting you can fit in a workout three or four times a week—even if it’s just a seven-minute HIIT routine.

So promise me you’ll give it a shot… because every move you make is a move in the right direction!